Wind machines are widely used in agricultural applications, often to prevent springtime frost damage to a crop by circulating the air near the crop. To supplement the circulation of air with a direct heating of the air, the wind machines have been fitted with heaters.
Prior wind machine devices with heating features include U.S. Pat. No. 3,067,541, to Smith, which includes heater fuel combustion along the trailing edges of the wind machine's propeller blades. To deliver the fuel into the rotating propeller, a concentric set of tubing is employed within a rotaryjoint. The tubing set includes a stationary pipe received within a rotating pipe. O-ring seals are positioned within the overlapping flared and butted portions of the pipes, within the rotary joint, as detailed in FIG. 6, therein. A significant problem with this central rotary joint is that it cannot be applied to a conventional wind machine. The Smith '541 apparatus does not require a drive shaft and so the central, rotary joint can occupy this axial position. However, the drive shaft for the conventional wind machine's propeller is typically positioned in the rotational center of the wind machine's connection to the tower.
Another heating wind machine is found in U.S. Pat. No. 3,296,739 to Wiegel, which discloses a burner mounted near the hub of the propeller. A rotary connection supplies fuel through the rotating, upper section of the fan. The rotary connection of Wiegel '739 is detailed in FIG. 4, therein. The connection includes a hollow sleeve that couples to a fuel supply pipe. The hollow sleeve conducts the fuel into the upper section where it communicates with a lateral passage. An O-ring between the hollow sleeve and an upper joint section establishes a fluid tight seal. The wind machine rotates on the tower or support about a vertical axis. The Wiegel rotary connection is a simple pipe connection and so must be positioned at the bulls-eye center of the wind machine's vertical axis of rotation. Weigel provides a source of mechanical power for the wind machine on the rotating, upper portion of the wind machine and so avoids the need for a drive shaft that extends upward, along the rotational axis of the support. A rotatable connection for delivering liquids and fuels for a tower mounted wind machine is needed that does not require location at the center of the wind machine's vertical axis of rotation.